Cover Image

Saved in:
Bibliographic Details
Main Authors: Wang, J., Xie, W. J., Cangemi, F., Coleiro, A., Li, H. L., Xu, Y., Han, X. H., Yang, H., Xin, L. P., Mao, X., Zheng, J., Jin, J. J., Li, G. W., Rodriguez, J., Tao, L., Cordier, B., Wei, J. Y., Bacon, P., Bellemont, N., Bouchet, L., Cai, H. B., Cavet, C., Dai, Z. G., Godet, O., Goldwurm, A., Guillot, S., Huang, L., Huang, M. H., Jiang, N., Liang, E. W., Lu, X. M., Schanne, S., Stum, S. Le, Qiu, Y. L., Wang, X. G., Wang, X. Y., Wu, C., Zhang, L., Zhang, S. N.
Format: Preprint
Published: 2026
Subjects:
Solar and Stellar Astrophysics
High Energy Astrophysical Phenomena
Online Access:https://arxiv.org/abs/2601.16558
Tags: Add Tag
No Tags, Be the first to tag this record!
Table of Contents:
  • Detection of stellar flares at hard X-ray is still rare at the current stage. A transient was recently detected by the hard X-ray camera, ECLAIRs onboard the SVOM mission at 11:39:01.2UT on 2025, January 09. Simultaneous monitor in the optical band on the ground by SVOM/GWAC and follow-up spectroscopy enable us to confirm that the transient is caused by a superflare on HD~22468, a RS CVn-type star. The bolometric energy released in the flare is estimated to be $\sim7.2\times10^{37}-1.7\times10^{38}\ \mathrm{erg}$. The hard X-ray spectra of the event at the peak can be reproduced by the ``apec'' model of a hot plasma with a temperature of $106^{+27}_{-22}$~MK. In the optical range, the H$α$ emission-line profile obtained at $\sim1.7$ hrs after the trigger shows a bulk blueshift of $-96\pm20\ \mathrm{km\ s^{-1}}$, which can be explained by either a chromospheric evaporation or a prominence eruption. The ejected mass is estimated to be $3.9\times10^{20}$ g for the evaporating plasma, and to be $3.2\times10^{21}\ \mathrm{g}<M_{\mathrm{p}}<8.8\times10^{21}\ \mathrm{g}$ for the erupted prominence.

Similar Items